The Devils Lake Basin is a 3,810-square-mile (mi2) closed basin (fig. 1) in the Red River of the North Basin. About 3,320 mi2 of the total 3,810 mi2 is tributary to Devils Lake; the remainder is tributary to Stump Lake.

Since glaciation, the lake level of Devils Lake has fluctuated from about 1,457 feet (ft) above sea level (asl), the natural
spill elevation of the lake to the Sheyenne River, to 1,400 ft asl (Aronow, 1957). Although no documented records of lake
levels are available before 1867, Upham (1895, p. 595), on the basis of tree-ring chronology, indicated that the lake level
was 1,441 ft asl in 1830. Lake levels were recorded sporadically from 1867 to 1901 when the U.S. Geological Survey
established a gaging station on Devils Lake. From 1867 to the present (1996), the lake level has fluctuated between a
maximum of 1,438.4 ft asl in 1867 and a minimum of 1,400.9 ft asl in 1940 (fig. 2). On July 31, 1996, the lake level was
1,437.8 ft asl, about 15.2 ft higher than the level recorded in February 1993 and the highest level in about 120 years.

Since 1993, the lake level of Devils Lake (fig. 2) has risen rapidly in response to above-normal precipitation from the summer of
1993 to the present, and 30,000 acres of land around the lake have been flooded. The above-normal precipitation also has
caused flooding elsewhere in the Devils Lake Basin. State highways near Devils Lake are being raised, and some local
roads have been closed because of flooding.

In response to the flooding, the Devils Lake Basin Interagency Task Force, comprised of many State and Federal agencies, was formed in 1995
to find and propose intermediate (5 years or less) solutions to reduce the effects of high lake levels. In addition to various
planning studies being conducted by Federal agencies, the North Dakota State Water Commission has implemented
a project to store water on small tracts of land and in the chain of lakes (Sweetwater Lake,
Morrison Lake, Dry Lake, Mikes Lake, Chain Lake, Lake Alice, and Lake Irvine). Most of the planning studies include options
to store water in the Devils Lake Basin and to provide an outlet to the Sheyenne River via Devils Lake or the Stump
Lakes. If an outlet is constructed, water-quantity and -quality issues will be considered in designing the operating
plan. Therefore, current and accurate hydrologic information is needed to assess the viability of the various options to
lower the level of Devils Lake.

Figure 1

Because of a large snowmelt runoff during the spring of 1987, the lake level of Devils Lake reached 1,428.8 ft asl (the highest
level since the 1870s) in August 1987. A severe drought began late in the summer of 1987,
and the level declined to 1,422.6 ft asl by February 1993 (fig. 2). During the drought, the volume of water in storage decreased
about 37 percent, from 884,000 acre-feet (acre-ft) in August 1987 to 558,400 acre-ft in February 1993.

The drought also caused lake-level declines on all lakes in the Devils Lake Basin, including the chain of lakes. For example,
the level of Dry Lake was below the outlet elevation (1,445.0 ft asl) to Channel A from June 15, 1988, through April 22,
1989, and from June 4, 1989, through about February 28, 1992. Crops were planted in the lakebed of Lake Irvine during part of
the drought. For 1988-91, streamflow in tributaries to the chain of lakes ranged from only 4 percent of the long-term
average at Mauvais Coulee near Cando to 28 percent of the long-term average at Starkweather Coulee near Webster.
Much-below-average streamflow into the chain of lakes and above-average evaporation from
the lake surfaces during most of the drought produced little flow out of the chain of lakes into Devils Lake. Combined
streamflow of Channel A and Big Coulee for 1988-92 (the period of rapid lake-level decrease) was only 26,000 acre-ft, and
inflow from Channel A into Devils Lake from June 1988 through February 1992 was only 271 acre-ft.

The 15.2-ft lake-level rise since February 1993 corresponds to a 937,600-acre-ft increase in storage in Devils Lake. The
estimated average annual inflow to Devils Lake for 1950-93 is 65,500 acre-ft. Estimated annual inflow is 296,000 acre-ft for
1993; 216,000 acre-ft for 1994; and 398,400 acre-ft for 1995. Total inflow to Devils Lake for 1993-95 accounts for
24 percent of all inflow to Devils Lake for 1950-95.

Unusually high lake levels have been recorded on the chain of lakes at times since February 1993. Record or near-record
maximum lake levels occurred late in the summer of 1993 and in the spring of 1995
on Sweetwater, Morrison, and Dry Lakes and on Lakes Alice and Irvine. For example, the maximum lake level for 1983-96 for
Dry Lake occurred in August 1993 when water from the lake spilled over the shoreline in
the northwest part of the lake. Water that spilled out of the lake entered the old drainage system and reached Devils Lake
via Mikes Lake, Chain Lake, Lake Alice, Lake Irvine, and Big Coulee.

Sporadic lake-level measurements were made on the Stump Lakes from 1949 through 1979 and from 1993 through 1995. Before
1995, the lake level of West Stump Lake ranged from about 1,394.0 ft asl in the dry years to about 1,400.0 ft asl in the
wet years, and the lake level of East Stump Lake ranged from about 1,382.0 ft asl in the dry years to about 1,385.0 ft asl
in the wet years. The lake-level variability of the Stump Lakes (3 to 6 ft) is less than the variability of Devils Lake (38 ft).
Based on lake-level measurements through 1995, no sustained, major lake-level changes occurred on the Stump Lakes from 1949 through 1992.

Although no streamflow gages exist in the Stump Lakes drainage basin, quarterly lake-level
measurements since 1993 and observations of local landowners and North Dakota State Water Commission and U.S.
Fish and Wildlife Service personnel indicate that a relatively large amount of tributary runoff into West Stump Lake occurred
late in the summer of 1993 and, by February 1994, the level of West Stump Lake was 1,395.8 ft asl. Runoff into West Stump
Lake filled that lake and flowed into East Stump Lake during late 1993 and throughout 1994. By January 1995, West and East
Stump Lakes were joined and the lake level was 1,398.0 ft asl. On July 22, 1996, the lake level of Stump Lake was 1,403.8 ft
asl, the highest level in about 75 years.

All of the options for a Devils Lake outlet require that water be discharged to the Sheyenne River
upstream of Warwick. The drainage area of the Sheyenne River Basin is 6,910 mi2. Lake Ashtabula (normal full-pool capacity,
70,200 acre-ft), formed by Baldhill Dam, is the only major impoundment in the basin. The dam is operated to provide flood
control, municipal water supplies, stream-pollution abatement, and recreation. The Devils Lake outlet will be designed to
operate when maximum flow in the Sheyenne River at the point of discharge is between about 200 and 500 cubic feet per second
(ft3/s). Thus, water discharged through the outlet will be limited to the maximum design flow in the Sheyenne River minus
the natural flow.

The long-term average annual streamflow of the Sheyenne River near Warwick is 57.2 ft3/s. Daily average streamflows for 1990
and 1995 (fig. 3) indicate the large variability between a dry year (1990) and a wet year (1995). During 1990, streamflow was
less than 50 ft3/s almost the entire year; however, in 1995, streamflow was greater than 500 ft3/s for 26 days and greater
than 200 ft3/s for 71 days.

In tributaries upstream of the chain of lakes, average dissolved-solids concentrations ranged from 361 milligrams per
liter (mg/L) for Starkweather Coulee (site 2; fig. 4) to 617 mg/L for Mauvais Coulee (site 3; fig. 4).
The concentrations forater samples collected during 1993-95 generally ranged from 200 to 450 mg/L during high flow and from 450 to 1,000 mg/L during low flow.

Dissolved-solids concentrations in Morrison Lake, Sweetwater Lake, Dry Lake, Lake Alice, and Lake Irvine are similar. Average
dissolved-solids concentrations ranged from 585 mg/L for Sweetwater Lake (site 4; fig. 4) to 768 mg/L for Lake Alice (site
5; fig. 4). The period of record for dissolved-solids data is much shorter for Morrison and Dry Lakes than for the other lakes
in the chain; thus, they are not included in figure 4. Dissolved-solids concentrations in Sweetwater Lake do not vary
seasonally, but those in Lakes Alice and Irvine do vary seasonally. In Lakes Alice and Irvine, concentrations in the
spring routinely were less than those during the remainder of the year. Seasonal variations indicate that the dissolved-solids
concentrations of Lakes Alice and Irvine may be influenced by the seasonal variability of tributary inflows and by the concentrating
effect of evaporation during the summer (Lent and Zainhofsky, 1995). Maximum concentrations (fig. 4) in the chain of lakes
usually occur in the winter because the lake levels are at or near annual minimums at the time of freezeup, and ice formation
increases the concentration of dissolved solids in the underlying water. Generally, average dissolved-solids concentrations (fig.
4) for the chain of lakes are higher than those for the tributaries to the lakes, and the variability of dissolved solids
in the chain of lakes is less than in the tributaries.

Dissolved-solids concentrations in Channel A (site 7; fig. 4) during 1993-95 ranged from 270 to 830 mg/L and averaged 467
mg/L. Concentrations in Big Coulee (site 8; fig. 4) averaged 461 mg/L but were less variable than those in Channel A. The
concentrations ranged from 290 to 570 mg/L, except for during low flow in January 1994 (720 mg/L) and during October 1994
(640 mg/L).

Devils Lake, which consists of several bays that are, to some extent, isolated from each other, is characterized by large
fluctuations in lake level and in concentrations of dissolved solids. Dissolved-solids concentrations
vary both spatially and temporally. Dissolved-solids concentrations generally increase from west to east in Devils Lake
and East Devils Lake as less-concentrated water enters the western part of the lake and becomes progressively more concentrated by
evaporation as it moves eastward. Average concentrations during 1988-90 ranged from about 3,400 mg/L at four sites west of Highway
57 (fig. 1) to about 10,000 mg/L in East Devils Lake (fig. 5). By the fall of 1995, dissolved-solids
concentrations in Devils Lake had decreased
dramatically, and concentrations in the western part of the lake ranged from about 1,280 mg/L in West Bay
to about 1,880 mg/L in Main Bay (fig. 1; North Dakota Department of Health, written commun., 1995).

Dissolved-solids concentrations generally are largest in winter when ions are concentrated
trated because of ice formation and smallest in spring when water is diluted because of icemelt,
surface-water inflow, and precipitation. The concentrations generally increase in summer and fall
when evaporation exceeds surface-water inflow and precipitation. Dissolved-solids concentrations of Devils Lake
generally fluctuate inversely with lake level.

The U.S. Geological Survey sampled West and East Stump Lakes sporadically from 1949 through 1979 and from 1993 through 1995.
In June 1949, a detailed study of West Stump Lake determined that the lake was uniform
in quality; dissolved-solids concentrations ranged from 5,950 to 6,090 mg/L. Since 1949, concentrations have ranged from 2,430
mg/L in May 1995 to 108,000 mg/L in September 1963 during a drought. In comparison, the dissolved solids in seawater is about
35,000 mg/L. On October 16, 1995, the concentra-tion in West Stump Lake was 4,210 mg/L (fig. 1).

Dissolved-solids concentrations in East Stump Lake have ranged from 17,600 mg/L
in July 1995 to 241,000 mg/L in July 1961. On October 16, 1995, the concentration in East Stump Lake was 18,200 mg/L
(fig. 1), which was similar to the 1919 concentration of 19,000 mg/L (Young, 1924) before the
West ans East Stump Lakes segmented. Since 1993, dissolved-solids concentrations have decreased dramatically in West and East Stump Lakes
because of dilution from the large amount of relatively fresh surface-water runoff.

Average dissolved-solids concentrations for water samples collected from the Sheyenne River near Warwick are about the same
as those for Big Coulee (site 8; fig. 4) and Channel A (site 7; fig. 4), but the variability is less in the
Sheyenne River (site 9; fig. 4). Concentrations for 266 samples collected from 1951 through 1995 from the Sheyenne River near
Warwick ranged from 150 to 950 mg/L and averaged 476 mg/L.

Spatial variability of dissolved solids in Devils Lake and the Stump Lakes is an important factor in
determining the pumping-plant size and outlet location to the Sheyenne River. For example, if 200 ft3/s of water
from the West Bay of Devils Lake is added to 200 ft3/s of water in the Sheyenne River near Warwick, the dissolved-solids
concentration in the river increases from 480 to 880 mg/L and the sulfate concentration increases from 96 to 350 mg/L (fig.
6). However, if the same amount of water is pumped from East Stump Lake, the dissolved-solids concentration in the river
increases from 480 to 9,300 mg/L and the sulfate concentration increases from 96 to 5,400 mg/L